JPH05287080A - Method for solid-phase polymerization of powdered polymer - Google Patents

Abstract

PURPOSE:To obtain a polymer having a uniform quality in a short time by conducting the solid-phase polymn. of a polymer powder by putting the powder into a tray, and inserting a specific thermal conductor into the powder to thereby transfer heat quickly to the powder from the atmosphere in a heating oven through the conductor. CONSTITUTION:The solid-phase polymn. of a polymer powder (e.g. a powder of a wholly arom. polyester obtd. by reacting p-acetoxybenzoic acid, 4, 4'- diacetoxydiphenyl, and terephthalic acid) is conducted by putting the powder into a tray and inserting a thermal conductor made of a metal having a thermal conductivity at 200 deg.C of 10 W/m.K or higher (e.g. aluminum) into the powder in a tray with the upper end of the conductor jutting out by at least 0.5cm from the upper surface of the powder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid phase polymerization method for powdery polymers. More specifically, the present invention relates to a novel solid-state polymerization method capable of producing a polymer having a small variation in quality in a short time.

[0002]

2. Description of the Related Art A method of solid-phase polymerizing a polyester polymer such as polyethylene terephthalate or polybutylene terephthalate in an inert gas has been conventionally known.

At this time, a tumbler method (Japanese Patent Laid-Open No. 56-
No. 43324) and a fluidized bed method, but these methods have the drawback that the structure of the device is complicated and the cost is high. In addition, the polymer tends to remain in the equipment, so every time you change the product type or grade, disassemble the equipment,
Needed cleaning. For this reason, these methods are not economical in terms of workability particularly in the production of a large amount of small quantities.

On the other hand, a method in which a polymer is placed in a stationary dish-shaped tray and the tray is inserted into a heating furnace to heat the polymer without stirring it to perform solid phase polymerization (hereinafter referred to as a stationary tray method) ) Is also considered. However, since the heat transfer of the polymer itself is poor, in this case, the productivity had to be sacrificed in order to reduce the variation in the quality of the polymer. That is, when a large tray was used or the thickness of the polymer layer placed in the tray was increased, a long heat treatment was required. Further, if the size of the tray and the thickness of the polymer layer are reduced, the treatment can be performed in a short time, but it takes time to fill and extract the polymer, and the amount that can be treated at once with a predetermined heating device is reduced. In any case, the conventional stationary tray system was not efficient for carrying out a large amount of solid-state polymerization of the polymer.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a method for overcoming these problems and carrying out solid-state polymerization of a polymer conveniently, economically and extremely advantageously, efficiently and producing a polymer of uniform and stable quality. Is provided.

[0006]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have made a material having good thermal conductivity when solid-phase polymerizing using a large tray. It has been found that the above problem can be solved by inserting a heat transfer body.

That is, according to the present invention, when a powdery polymer is filled in a tray and solid-phase polymerization is carried out, a heat transfer material made of a metal having a thermal conductivity at 200 ° C. of 10 W / m · K or more is powdery. The present invention relates to a solid-state polymerization method characterized by being inserted into a polymer.

The polymer to which the solid-state polymerization method of the present invention can be applied is not particularly limited, and specific examples thereof include polyester, polyamide, polyamideimide, polyimide, polyphenylene sulfide and the like.

As the polyester, polyethylene terephthalate, polybutylene terephthalate, poly-m-
Polyesters such as phenylene terephthalate, poly-p-phenylene isophthalate and poly 1,4-cyclohexanedimethylene terephthalate, polyesters obtained from aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid and 2-hydroxy 6-naphthoic acid, and Obtained from these and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid, and aromatic dihydroxy compounds such as hydroquinone, resorcin, 4,4′-dihydroxydiphenyl and 2,6-dihydroxynaphthalene. Examples include liquid crystal polyester.

The polymer is preferably in the form of powder, particles or pellets. Specifically, the average particle size of the polymer is 0.05 to 5 mm, preferably 0.1 to 2 mm. Here, these are collectively referred to as a powdery polymer.

When conducting solid-state polymerization, the heat transfer body is inserted into the powdery polymer to bring the heat transfer body and the powdery polymer into contact with each other. Furthermore, it is preferable that the upper end of the heat transfer member is above the surface of the polymer layer by 0.5 cm or more, preferably 1 cm or more. Further, it is preferable to bring the heat transfer member into contact with the bottom plate and side wall plate of the tray. This makes it possible to obtain a powdery polymer having a uniform and stable quality.

The material of the heat transfer material has a thermal conductivity at 200 ° C. of 10 W / m · K or more, preferably 100 W / m.
A metal of m · K or higher is preferable. Further, considering strength, operability, price, etc., aluminum, copper, zinc, stainless steel and alloys thereof are preferable, and aluminum and alloys thereof are particularly preferable.

Examples of the shape of the heat transfer body include a plate shape, a net shape, and a rod shape. Among these, the ease with which the heat in the heating furnace atmosphere is transferred to the powdery polymer, and the transfer of heat from the powdery polymer after inserting the heat transfer material into the powdery polymer or completing the solid-state polymerization. The plate shape is preferable in consideration of operability such as taking out the heat element. Particularly, a plate-shaped material having a thickness of 0.5 to 10 mm, preferably 1 to 5 mm is preferable. A strip-shaped heat transfer plate can be inserted into the polymer filled in the tray, but a combination of a plurality of strip-shaped heat transfer plates as shown in FIG. It is preferable because it is excellent. FIG. 2 shows a schematic cross-sectional view of a state in which the lattice-shaped heat transfer plate is inserted in the powdery polymer filled in the tray.

When the heat transfer plate is used in the vertical direction, the distance between the tray and the heat transfer plate and the heat transfer plate is preferably 30 cm or less, particularly 20 cm or less. Here, the space between the heat transfer plates is the space between the strips in the case of strips, and in the case of combining a plurality of strip-shaped heat transfer plates as shown in FIG. The distance between the heat transfer plates facing each other.

As a method for inserting the heat transfer plate into the polymer filled in the tray, it is preferable to insert the heat transfer plate so as to be in close contact with the side wall plate and the bottom plate of the tray. However, there is no particular problem even if some polymer layer is present between the tray and the heat transfer plate. The height of the heat transfer plate is 0.5 cm or more, preferably 1 cm or more from the polymer layer surface at the upper end of the heat transfer plate when the heat transfer plate is inserted so as to be in close contact with the bottom plate of the tray.
It is preferable to go above the cm.

The shape and size of the tray are not particularly limited, but in consideration of the shape of a general heating device and the operability of inserting a heat transfer plate, a rectangular parallelepiped shape with an open top (heavy box) is used. Shape) is preferred. The material of the tray has a thermal conductivity of 10 W / mK or more at 200 ° C,
A metal of 100 W / m · K or more is preferable. Further, considering strength, operability, price, etc., aluminum, copper, zinc, stainless steel and alloys thereof are preferable, and aluminum and alloys thereof are particularly preferable. The solid-state polymerization atmosphere is preferably an inert gas atmosphere.

By inserting the heat transfer plate in this way,
Thicken the polymer layer per tray to increase the filling amount,
Furthermore, the processing time has been greatly shortened, and it has become possible to produce polymers of uniform quality, which is extremely valuable industrially.

[0018]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. The physical properties in the examples were measured by the following methods.

Flowing temperature: Shimadzu's high-performance type
Measured with a flow tester CFT-500 type, 4 ° C /
Resin heated and melted at a heating rate of 100
cm ²The nozzle with an inner diameter of 1 mm and a length of 10 mm under
At the point of melting, the melt viscosity shows 48,000 poise.
Temperature. The lower the temperature, the greater the fluidity
Is.

Optical anisotropy: The optical anisotropy of the resin in a molten state was determined by observing the powdered resin placed on a heating stage under polarized light at a temperature of 10 ° C./min by visual observation. Then, the liquid crystal starting temperature was determined. In addition, when it was not completely melted under standing, it was carried out under pressure by using spring pressure.

Tensile strength, heat distortion temperature (HDT): A
STM4 tensile dumbbell, test piece for HDT measurement (127
(mm length × 12.7 mm width × 6.4 mm thickness) was molded and measured according to ASTM D638 and ASTM D648, respectively.

Reference Example 1 (Production of Liquid Crystal Polyester A) P-acetoxybenzoic acid 10.81 kg (60 mol),
5,4 kg of 4,4'-diacetoxydiphenyl (20
Mol) and 3.32 kg (20 mol) of terephthalic acid were charged into a 50 l SUS-316L polymerization tank having a comb-shaped stirring blade. The temperature was raised in a nitrogen gas atmosphere and the temperature was raised from 180 ° C. with stirring at a rate of 1 ° C./min to distill off acetic acid produced as a by-product and polymerization was carried out at 300 ° C. for 60 minutes. After that, the system was closed, the internal pressure of the tank was kept at 1 kg / cm ² G with nitrogen, the valve at the bottom of the polymerization tank was opened, and the reaction product was extracted into a stainless tray with a thickness of about 1 cm. The yield of this reaction product was 13.41 kg, which was 99.2% of the theoretical yield. This was crushed with a hammer mill manufactured by Hosokawa Micron Co., Ltd. to an average particle size of about 0.5 mm, and a wholly aromatic polyester (hereinafter referred to as "liquid crystal polyester A") having a flow temperature of 285 ° C. and comprising the following repeating structural units. Got This polymer is 305 ° C under pressure
Above, optical anisotropy was shown. That is, the liquid crystal starting temperature is 3
It was 05 ° C. The repeating structural unit of the liquid crystal polyester A is as shown in the general formula 1.

[0023]

[Chemical 1]

Reference Example 2 (Production of Liquid Crystal Polyester B) P-acetoxybenzoic acid 10.81 kg (60 mol),
5,4 kg of 4,4'-diacetoxydiphenyl (20
Mol), 2.49 kg (15 mol) of terephthalic acid and 0.83 kg (5 mol) of isophthalic acid were charged, and polymerization was carried out at 300 ° C. for 60 minutes in the same manner as in Reference Example 1, and the reaction product was extracted.
The yield of this reaction product was 13.11 kg, which was 9 the theoretical yield.
It was 7.0%.

This was crushed with a hammer mill manufactured by Hosokawa Micron Co., Ltd. to an average particle size of about 0.5 mm, and a wholly aromatic polyester (hereinafter referred to as "liquid crystalline polyester B") having a flow temperature of 270 ° C. and consisting of the following repeating structural units. I got). Further, this polymer exhibited optical anisotropy at 290 ° C. or lower under pressure, and the liquid crystal starting temperature was 290 ° C. The repeating structural unit of the liquid crystal polyester B is as shown in the general formula 2.

[0026]

[Chemical 2]

Example 1 As a material for the tray, A specified by JIS H4000
Aluminum of 1080P was used. The thermal conductivity of the aluminum at 200 ° C. is 230 W / m · K (0.5
5 cal / sec · cm · ° C). Inner size 120 cm
Liquid crystal polyester A repeatedly synthesized under the conditions of Reference Example 1 on an aluminum tray having a size of 120 cm and a depth of 10 cm.
Was charged (polymer thickness is 6.5 cm). Then, using an aluminum plate with a length of 119 cm and a height of 8 cm, 20
A heat transfer plate assembled in a grid pattern with a cm interval was inserted into contact with the bottom plate of the tray. The upper end of the heat transfer plate was projected 1.5 cm above the upper surface of the powdery polymer.

This was placed in an oven under a nitrogen atmosphere, heated from room temperature to 250 ° C. in 1 hour, heated to 320 ° C. in 4 hours, kept at 320 ° C. for 5 hours, and further cooled to 200 ° C. , Solid phase polymerization was completed.

There was no sintering as a whole, and it could be recovered as a clean powder, and the weight loss was 2.5%. When the polymer of the surface portion of the interstitial center portion of this polymer and the polymer of the intermediate layer portion were sampled and the flow temperature was measured, each was 376 ° C
The difference was small at 374 ° C, and the flow temperature of the polymer in which all the components were mixed was 375 ° C, and the liquid crystal initiation temperature was 396 ° C.

Next, 600 g of this polymer and 400 g of glass fiber (EFH75-01 manufactured by Central Glass Co., Ltd.)
And a twin-screw extruder (PCM-3 manufactured by Ikegai Tekko KK)
0) was melt-kneaded at 350 ° C. to obtain pellets.
Using an injection molding machine (PS40E5ASE manufactured by Nissei Plastic Industry Co., Ltd.), these pellets were heated to a cylinder temperature of 390.
At 0.8 ° C. and a mold temperature of 130 ° C., a tensile strength, HDT, and a 0.8 mm-thick strip test piece for evaluating the presence or absence of blistering in a thin-walled (0.8 mm-thick) molded product were molded and measured by the above method.

The results are shown in Table 1. The physical properties were generally higher than those of Comparative Example 1, and no blister was observed in the thin-walled molded product.

Example 2 Solid-state polymerization was conducted under the same conditions except that the distance between the heat transfer plates used in Example 1 was narrowed to 10 cm. At this time, the weight loss of the polymer was 2.6% and there was no sintering or the like.

The flow temperature of the polymer sampled at the surface portion of the interstitial center portion of this polymer and the flow temperature of the polymer sampled at the intermediate layer portion are 377 ° C. and 377 ° C., respectively. The liquid crystal starting temperature was 400 ° C.

This polymer was melt-kneaded and injection-molded under the same conditions as in Example 1 to prepare test pieces, and their physical properties were measured. The results are shown in Table 1, and the physical properties were generally good.

Example 3 Solid-state polymerization was conducted under the same conditions except that the distance between the heat transfer plates used in Example 1 was widened to 40 cm.

The weight loss of the polymer at this time is 2.0%
At this time, the flowing temperatures of the sampling polymer in the surface portion and the intermediate layer portion are 372 ° C. and 364 ° C., respectively, and the flowing temperature of the total amount of mixed polymer is 366 ° C.
It was ℃.

This polymer was melt-kneaded and injection-molded under the same conditions as in Example 1 to obtain each test piece, and its physical properties were measured. As a result, several blisters were observed on the surface of the thin-walled molded product. The results are shown in Table 1.

Comparative Example 1 Solid-state polymerization was carried out under the same conditions as in Example 1 except that no heat transfer plate was used. The weight loss of the polymer at this time was 1.7%,
The flow temperatures of the sampling polymer in the surface layer and the intermediate layer of the tray were 369 ° C. and 358 ° C., respectively, and the total mixed polymer flow temperature was 360 ° C., and the liquid crystal starting temperature was 380 ° C.

This polymer was also melt-kneaded under the same conditions as in Example 1 and injection-molded at 390 ° C., but there were many burrs in the entire molded product, and the product was molded at 380 ° C. to obtain each test piece. In general, the physical properties were low, and many blisters were observed in the thin-walled molded product. The results are shown in Table 1.

Comparative Example 2 As in Comparative Example 1, without using a heat transfer plate, the amount of liquid crystal polyester A charged was 20 kg (polymer thickness was 2.5 cm).
Solid phase polymerization under the same conditions for all others.

At this time, the weight loss was 2.5%, the flow temperature of the whole mixed polymer was 376 ° C., and the liquid crystal starting temperature was 3%.
It was 98 ° C. This polymer was melt-kneaded and injection-molded under the same conditions as in Example 1 to obtain each test piece. All had no problems and had good physical properties, and no blister was observed in the thin-walled molded product. The results are shown in Table 1, and the production amount was about 40% of that of Example 1, 2 or 3, and the production efficiency was poor.

Example 4 53 kg of liquid crystal polyester B repeatedly synthesized under the conditions of Reference Example 2 was charged in the same tray as in Example 1 (polymer thickness was 6.5 cm). Next, the same lattice spacing 2 as in Example 1
A 0 cm heat transfer plate was inserted in contact with the bottom plate of the tray. The upper end of the heat transfer plate is 1.5 from the upper surface of the powdery polymer.
It was above the cm.

This was placed in an oven under a nitrogen atmosphere, the temperature was raised from room temperature to 250 ° C. in 1 hour, and then 2 hours in 3 hours.
The temperature was raised to 75 ° C. and the temperature was maintained at 275 ° C. for 5 hours to complete the solid phase polymerization. The weight loss in the solid state polymerization was 1.4%, and when the polymer of the surface part of the interstitial center part of the polymer and the polymer of the intermediate layer part were sampled and the flow temperature was measured, it was 330 ° C and 329 ° C, respectively. The whole mixture was 330 ° C., and a polymer having no unevenness was obtained. The liquid crystal starting temperature of this polymer was 350 ° C.

Next, as in Example 1, this polymer 60 was used.
0 g and a glass fiber temperature of 400 g were mixed, melt-kneaded at 330 ° C. using a twin-screw extruder to obtain pellets, and injection-molded at a cylinder temperature of 350 ° C. and a mold temperature of 130 ° C. The physical properties of the molded product are shown in Table 2. The appearance was clean and the physical properties were good.

Example 5 Solid-state polymerization was conducted under the same conditions except that the distance between the heat transfer plates used in Example 4 was narrowed to 10 cm. At this time, the weight loss of the polymer was 1.5%, and the flow temperatures of the polymer sampled at the surface portion of the interstitial center portion and the intermediate layer portion of this polymer were 331 ° C and 330 ° C, respectively, and the total mixture was 332 ° C. It was ℃. The liquid crystal onset temperature of this polymer is 3
It was 53 ° C.

This polymer was melt-kneaded under the same conditions as in Example 1 and injection-molded to prepare a test piece, and its physical properties were measured.
The results are shown in Table 2, and the physical properties were generally good.

Comparative Example 3 Solid-state polymerization was carried out under the same conditions as in Example 4 except that a heat transfer plate was not used. At this time, the weight loss of the polymer was 1.1%, the flow temperatures of the polymer sampled in the surface layer in the center of the tray and in the intermediate layer were 324 ° C and 316 ° C, respectively, and the total mixture was 318 ° C. .. The liquid crystal initiation temperature of this polymer was 336 ° C. This polymer was also melt-kneaded and injection-molded under the same conditions as in Example 4, but each test piece had some burrs, and the physical properties were generally low, and the surface of the 0.8 mm-thick thin-walled molded product was Blisters were seen. The results are shown in Table 2.

Comparative Example 4 Solid-state polymerization was carried out in the same manner as in Comparative Example 3 except that the amount of the liquid crystal polyester B charged was 20 kg (polymer thickness was 2.5 cm). At this time, the weight loss was 1.6%, the flow temperature of the whole mixed polymer was 334 ° C, and the liquid crystal starting temperature was 3
It was 56 ° C.

Similarly, this polymer was melt-kneaded and injection-molded to measure each physical property. The physical properties are shown in Table 2, but all were good. However, as in Comparative Example 2, the productivity was extremely poor.

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

According to the present invention, when the powdery polymer is solid-phase polymerized by the stationary tray method, by inserting the heat transfer material into the powdery polymer, the heat transfer material is inserted through the heat transfer material. The heat of the atmosphere of the heating furnace can be quickly transferred to the powdery polymer, and the polymer with a small quality variation can be manufactured rationally and economically. When there is no heat transfer material as in Comparative Example, a polymer of stable quality cannot be obtained, and in order to obtain a polymer of stable quality, it is necessary to reduce the amount charged per tray very much. Is a disadvantage to On the other hand, according to the present invention, as is apparent from the examples, it is possible to efficiently manufacture the apparatus with a simple apparatus and without any problem in workability.

[Brief description of drawings]

FIG. 1 is a perspective view of a grid-shaped heat transfer plate.

FIG. 2 is a schematic cross-sectional view of a state in which a lattice-shaped heat transfer plate is inserted in a powdery polymer filled in a tray.

[Explanation of symbols]

 1. Heat transfer plate. 2. tray. 3. Powdered polymer.

Claims (2)

[Claims] 1. A thermal conductivity at 200 ° C. of 10 W / m · when a powdery polymer is packed in a tray and solid-phase polymerized.
A solid-state polymerization method, characterized in that a heat conductor made of a metal of K or more is inserted into a powdery polymer. 2. The solid-state polymerization method according to claim 1, wherein the upper end of the heat transfer member is protruded above the upper surface of the polymer filled in the tray by 0.5 cm or more.